This is WAY easier than you are making it out to be!
1/2" PVC sounds like serious
overkill, you could be using 14 gauge wire to make wings that size and shape and do just fine. Especially since they aim down.
As to "straps around the waist" you are over thinking again, all you need is a good wide belt. I'd get an military surplus canvas one like this: https://www.armysurplusworld.com/ext...e-black-buckle
They are easy to cut to a shorter length and the buckle is reasonably smooth. Cotton will be more comfortable under clothes than vinyl. Bonus, it'll be reasonably easy to attach the wings to it if you switch to wire.